Multi-filament splice enclosures

ABSTRACT

A multi-filament splice enclosure (11) comprising a box-like body (12) having an opening lid (13) allowing access to organiser trays (24) arranged in a stack within the enclosure. The organiser trays are arranged on guide means (28), preferably mounted on a carrier (30) that allows the stack of trays to be raised for access thereto when the lid (13) is open. The trays (24) are removeable from the carrier (30) for access to the individual filaments.

BACKGROUND OF THE INVENTION

The present invention relates to enclosures for multi-filament cablesplices, and in particular to an enclosure for a splice between opticalfibre cables.

In splicing arrangements for multi-filament cables especially opticalfibres, the joined optical fibres are arranged on organiser trays whichretain the optical fibres at the correct minimum bend radius. Thesedevices provide easy access to the individual fibres contained withinthe trays and each tray can be marked to identify the different fibres.The trays are typically stacked next to one another and may be hinged toa carrier allowing them to move relative to one another for access tothe individual organiser trays.

Such a device is shown in EP-A-159857, and in U.S. Pat. No. 4,266,853.

SUMMARY OF THE INVENTION

The present invention provides an enclosure for a splice formultifilament cables giving improved access to organiser trays withinthe enclosure.

Accordingly there is provided a multi-filament (preferably an opticalfibre, but possibly a copper wire or other filament) splice enclosurehaving a normally closed opening allowing access to a plurality offilament organiser trays arranged in a stack within the enclosure, theorganiser trays being mounted within the enclosure on guide meansallowing the stack of trays to be raised through the opening when opento provide access to the or each organiser tray.

Preferably the enclosure comprises a substantially box-like body with anopening lid hinged or otherwise moveably fixed at one side of the box,and the stack of trays is accessible through the lid when open, thetrays being liftable away from, and preferably out, of the interior ofthe box.

The guide means may have an abutment thereon to limit the upwardmovement of the stack of trays.

Preferably the guide means is formed integrally with the box-like body(although it may be formed separately and subsequently bonded, boltedriveted or interlocked with it) which is a preferably plastics moulding,preferably formed from polypropylene or polyamide, but other polymermaterials such as high density polyethylene, acrylics etc. may besuitable.

The stack of trays may be locked in a lifted position by a releasabledetent. The detent may be formed on at least one of the guide means.

The organiser trays may be arranged in a carrier unit which is in turnmounted on the guide means. In this case the detent could be formed onthe carrier unit.

The organiser trays are moveable within the carrier unit, preferably bybeing pivoted or slidably fixed thereto, for access to the filaments.

The splice is especially useful in the field of optical fibres, forexample in a telecommunications network, and the invention is applicableto both butt splice enclosures and in-line splice closures.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by way of example only and withreference to the accompanying drawings, FIGS. 1 and 2A-2B of which shownin isometric view and in transverse sections respectively an enclosurefor a splice for multi-filament cables, showing the enclosure in an opencondition with the stack of organiser trays in a raised position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The enclosure 11 illustrated is for an in-line cable splice but theinvention is not restricted to in-line splices. The enclosure 11 may bemanufactured from a plastics material such as polypropylene, orpolyamide and comprises a box-like body 12 having a lid 13 which ishinged to the body at one side by hinges 14. The other side of the lidaway from the hinged 14 has lugs 15 thereon which are engageable withlocking nuts 16 and screw-threaded struts 17 pivoted on the other sideof the box-like body 12 to hold the lid in a closed position.

The lid 13 and body 12 have interengaging rims 18, 19 which seal theinterior of the box against the ingress of moisture. If necessary asealing aid for example, a sealing material such as silicone or otherrubber, gel, or mastic may be applied to the interengaging surfaces.Other sealing aids that may be used are shaped rubber gaskets, sealingrings etc.

Cable ports 21, 22 are located at the ends of the body 12. A pluralityof multi-filament cables such as optical fibre cables can enter and exitthe interior of the body through cable ports 21, 22. An external jacketof the cables is secured at each end of the body 12 by a clamping device23 held in position by a similar closure mechanism to that of the lid,and the cables may be sealed in the respective ports by a surroundingseal. The surrounding cable seal may be of any suitable form and may bea elastomeric resiliently deformable preformed seal, such as silicone orother rubber or gel, or a sealant such as a mastic material.

The optical fibres are spliced and the individual spliced fibres areplaced on rectangular or other shaped organiser trays 24 which are eachadapted to retain and store the slack in at least one fibre that wasrequired for original alignment and splicing remote from the enclosureor that might be required for repair or further splice work onindividual fibres.

The organiser trays 24 are arranged in a stack one upon the other, withthe organiser trays being optionally arranged in back-to-back pairs 24a24b, 24c 24d, etc. Between adjacent pairs of organiser trays 24a 24b,24c 24d etc. there may be located partition walls 25 held apart alongone longitudinal edge by spacers 29. End walls 26, 27 are located at theupper and lower ends of the stack. In this example there are four pairsof organiser trays, but other numbers of pairs could equally beutilised. The walls on 26, 27 and 25 on each side of a pair of trays,and the spacers 29 form housings 33 into which the organiser trays (24)can be retracted. The trays 24 and walls and spacers 25, 26, 27, 29together form a cassette-like carrier unit or stack 30 which is mountedon a plurality of guide members 28 located one at each corner of thecassette-like unit 30. These guide members 28 have guide surfaces whichslideably support and guide the cassette-like unit 30 allowing the unit30 to be raised out of the interior of the body 12. When in the raisedcondition the lower end wall 27 engages abutments 32, in the upper endportions of the guides 28 to limit the upward movement of the unit 30.The raising of the unit 30 could be assisted by the provision of aresilient body such as a plastics material or metal leg spring or coilspring between the lower end wall 27 and the base of the box-like body12.

The cassette-like unit (30) may be retained in its fully raised positionby resilient means such as a spring 31 or a releasable detent, whichbears against or engages the lower end plate 27. The cassette unit 30may be lowered back into the interior of the box simply by releasing thedetent. The spring 31 may automatically raise the cassette-like unit 30on release of a detent.

The detent may also be engageable with the partition walls 25 so thatthe cassette unit may be held in various partially raised positions Whenin a raised position a tray 24 may be exposed for access to its fibresor removed from the unit by, for example, pivoting that tray 24 at acorner. Each tray is preferably able to pivot in a plane normal to thedirection in which the stack is raised.

FIGS. 2A and 2B show cross-sections at different positions through theclosure of FIG. 1.

I claim:
 1. A multi-filament optical fiber splice enclosure having anopening allowing access to a plurality of filament organizer traysarranged in a stack within the enclosure, the enclosure including guidemeans associated with the enclosure and having the stack of organizerstrays mounted on the guide means for guiding the stack of trays to araised position through the opening to provide access to each organizertray, the guide means including an abutment associated therewith forlimiting the upper movement of the stack of trays so that the lower mostaccessible organizer tray of the stack of trays remains closely adjacentupper peripheries of a base of the enclosure in the raised position, aplurality of ports positioned in at least two side walls of theenclosure for inserting multi-filament optical fiber cablestherethrough, and a plurality of clamping devices respectivelypositioned adjacent a respective corresponding one of the plurality ofports for clamping multi-filament cables inserted there through.
 2. Anenclosure as claimed in claim 1, wherein the stack of trays can belocked in a raised position by a releasable detent.
 3. An enclosure asclaimed in claim 2 wherein the stack can be locked in a selected one ofa plurality of various raised positions.
 4. An enclosure as claimed inclaim 1 wherein organizer trays are arranged in a carrier unit, which ismounted in the guide means.
 5. An enclosure as claimed in claim 4,wherein the carrier unit is subdivided into a plurality of housings andinto each of such housing at least one organizer tray is located.
 6. Anenclosure as claimed in claim 5, wherein there is a pair of back-to-backorganizer trays located in each housing.
 7. An enclosure as claimed inclaim 1, wherein an organizer tray can be moved pivotally or by slidingrelative to another organizer tray to allow access to a filament on atleast one of those trays.
 8. An enclosure as claimed in claim 7, whereinthe organizer trays are pivotally connected to a carrier unit which ismounted in the guide means.
 9. An enclosure as claimed in claim 7,wherein an axis of rotation of the organizer tray is substantiallyparallel to the guide means so that the organizer trays rotate in aplane perpendicular to a direction of movement of the stack duringraising thereof.
 10. An enclosure as claimed in claim 1, wherein theorganizer trays are substantially rectangular in shape, and there arefour guide means located one at each corner of the filament organizertrays in the stack.
 11. An enclosure as claimed in claim 1, wherein theenclosure has a substantially box-like body with an opening lid moveablyfixed thereto at one side thereof and the stack of organizer trays isaccessible through said lid when open, the trays being liftable awayfrom the interior of the box.